A179371 - cp's OEIS frontend

A179371 a(1) = 1; a(n) = smallest positive integer not already used which has a prime signature different from both a(n-1) and a(n-1)+1.

n	a(n)
1	1
2	4
3	6
4	8
5	2
6	9
7	3
8	10
9	12
10	14
11	5
12	16
13	15
14	7
15	18
16	21
17	11
18	22
19	20
20	13
21	24
22	17
23	25
24	19
25	26
26	23
27	27
28	29
29	28
30	30
31	32
32	31
33	33
34	36
35	34
36	37
37	40
38	35
39	41
40	38
41	42
42	39
43	43
44	46
45	44
46	47
47	45
48	48
49	50
50	49
51	51
52	53
53	52
54	54
55	59
56	55
57	60
58	56
59	61
60	63
61	57
62	64
63	66
64	58
65	68
66	67
67	62
68	70
69	65
70	71
71	69
72	72

[1, 4, 6, 8, 2, 9, 3, 10, 12, 14, 5, 16, 15, 7, 18, 21, 11, 22, 20, 13, 24, 17, 25, 19, 26, 23, 27, 29, 28, 30, 32, 31, 33, 36, 34, 37, 40, 35, 41, 38, 42, 39, 43, 46, 44, 47, 45, 48, 50, 49, 51, 53, 52, 54, 59, 55, 60, 56, 61, 63, 57, 64, 66, 58, 68, 67, 62, 70, 65, 71, 69, 72]

cp's OEIS Frontend

A179371 a(1) = 1; a(n) = smallest positive integer not already used which has a prime signature different from both a(n-1) and a(n-1)+1.

Table of values

List of values

n	a(n)
1	1
2	4
3	6
4	8
5	2
6	9
7	3
8	10
9	12
10	14
11	5
12	16
13	15
14	7
15	18
16	21
17	11
18	22
19	20
20	13
21	24
22	17
23	25
24	19
25	26
26	23
27	27
28	29
29	28
30	30
31	32
32	31
33	33
34	36
35	34
36	37
37	40
38	35
39	41
40	38
41	42
42	39
43	43
44	46
45	44
46	47
47	45
48	48
49	50
50	49
51	51
52	53
53	52
54	54
55	59
56	55
57	60
58	56
59	61
60	63
61	57
62	64
63	66
64	58
65	68
66	67
67	62
68	70
69	65
70	71
71	69
72	72

n	a(n)
1	1
2	4
3	6
4	8
5	2
6	9
7	3
8	10
9	12
10	14
11	5
12	16
13	15
14	7
15	18
16	21
17	11
18	22
19	20
20	13
21	24
22	17
23	25
24	19
25	26
26	23
27	27
28	29
29	28
30	30
31	32
32	31
33	33
34	36
35	34
36	37
37	40
38	35
39	41
40	38
41	42
42	39
43	43
44	46
45	44
46	47
47	45
48	48
49	50
50	49
51	51
52	53
53	52
54	54
55	59
56	55
57	60
58	56
59	61
60	63
61	57
62	64
63	66
64	58
65	68
66	67
67	62
68	70
69	65
70	71
71	69
72	72

n	a(n)
1	1
2	4
3	6
4	8
5	2
6	9
7	3
8	10
9	12
10	14
11	5
12	16
13	15
14	7
15	18
16	21
17	11
18	22
19	20
20	13
21	24
22	17
23	25
24	19
25	26
26	23
27	27
28	29
29	28
30	30
31	32
32	31
33	33
34	36
35	34
36	37
37	40
38	35
39	41
40	38
41	42
42	39
43	43
44	46
45	44
46	47
47	45
48	48
49	50
50	49
51	51
52	53
53	52
54	54
55	59
56	55
57	60
58	56
59	61
60	63
61	57
62	64
63	66
64	58
65	68
66	67
67	62
68	70
69	65
70	71
71	69
72	72